18-4-2011 – Dominion Virginia Power announced yesterday that its nuclear power plant in Surry, Virginia could be offline for a number of days while repairs are made to its electrical switchyard, which was damaged by a recent tornado.When the tornado touched down in the Surry station’s switchyard on Saturday, the reactors at the power station automatically shut down. According to the Nuclear Regulatory Commission, the damage “interrupted” the station’s connections to off-site power from the electrical grid.

Fortunately, the tornado did not directly hit the two nuclear reactors. The Surry Power Station is close to 50 miles southeast of Richmond.

The Richmond-Times Dispatch reported that 1 of the units had already been scheduled to go offline Saturday to refuel. The second reactor is scheduled to come back online when the switchyard repairs are completed.

This incident highlights, again, the precariousness of nuclear power in the face of natural disasters. Had the tornado hit one or both of the nuclear reactors, the damage could have been immense.

US tornadoes force shutdown of two nuclear reactors in Virginia

US tornadoes were most destructive in North Carolina, where Deborah Dulow, above, was left to survey the damage to her father’s house. Photograph: Jim R Bounds/AP

A US nuclear power company has disclosed that one of the tornadoes that hit the US at the weekend, killing at least 45 people and causing widespread damage, forced the shutdown of two of its reactors.

The series of tornadoes that began in Oklahoma late last week barrelled across the country, with North Carolina, where 22 people died, the worst-hit state.

The US nuclear safety regulator said on Mondayit was monitoring the Surry nuclear power plant in Virginia. Dominion Virginia Power said the two reactors shut down automatically when a tornado cut off power to the plant. A backup diesel generator kicked in to cool the fuel. The regulator said no radiation was released and staff were working to restore electricity to the plant.

The tornadoes were among the worst in the US in the past two decades. Last year, 10 people died in a tornado in Mississippi, while 57 were killed in North and South Carolina in 1984 and 330 across the south in 1974.

Two of the survivors of this year’s storms, Audrey McKoy and her husband Milton, who live near Raleigh, North Carolina, told the Associated Press they had seen the tornado bearing down on them over the tops of pine trees. At a nearby farm, winds were lifting pigs and other animals into the sky. “It looked just like The Wizard of Oz,” McKoy said.

They took shelter in their laundry room. After they emerged, disorientated, they realised that the tornado had turned their mobile home around.

The national weather centre in Raleigh issued detailed descriptions of the tornadoes and their paths of destruction.

One of them, with winds greater than 100mph, destroyed trees, ripped off roofs and wrecked power lines. It hit Shaw University in Raleigh and then strengthened to 110mph. “Snapped trees crashed on to and through numerous homes all along the path. It is in this area where three fatalities were reported when two mobile homes were thrown 30 to 50ft [nine to 15 metres]. Nearly all of the mobile homes in the park sustained some type of damage,” the weather report said.

Thousands of workers from the Federal Emergency Management Agency, the national disaster organisation, are being deployed in North Carolina to assess the damage.

US nuclear plant shuts safely as tornado hits

18 April 2011 –Both units at Dominion Virginia Power’s Surry nuclear plant in Virginia shut down automatically as designed when an apparent tornado touched down at the plant’s switchyard, cutting off external electricity supplies to the station. Backup diesel generators started up immediately to provide the necessary power to keep the two pressurised water reactors in a safe and stable condition. The tornado did not strike the nuclear units themselves, although their steel-reinforced concrete containment buildings are designed to withstand such natural events. Off-site power sources were subsequently restored to each unit.

The US nuclear safety regulator said on Monday it was monitoring the Surry nuclear power plant in Virginia. Dominion Virginia Power said the two reactors shut down automatically when a tornado cut off power to the plant. A backup diesel generator kicked in to cool the fuel. The regulator said no radiation was released and staff were working to restore electricity to the plant.

The tornadoes were among the worst in the US in the past two decades. Last year, 10 people died in a tornado in Mississippi, while 57 were killed in North and South Carolina in 1984 and 330 across the south in 1974.

Two of the survivors of this year’s storms, Audrey McKoy and her husband Milton, who live near Raleigh, North Carolina, told the Associated Press they had seen the tornado bearing down on them over the tops of pine trees. At a nearby farm, winds were lifting pigs and other animals into the sky. “It looked just like The Wizard of Oz,” McKoy said.

They took shelter in their laundry room. After they emerged, disorientated, they realised that the tornado had turned their mobile home around.

The national weather centre in Raleigh issued detailed descriptions of the tornadoes and their paths of destruction.

One of them, with winds greater than 100mph, destroyed trees, ripped off roofs and wrecked power lines. It hit Shaw University in Raleigh and then strengthened to 110mph. “Snapped trees crashed on to and through numerous homes all along the path. It is in this area where three fatalities were reported when two mobile homes were thrown 30 to 50ft [nine to 15 metres]. Nearly all of the mobile homes in the park sustained some type of damage,” the weather report said.

Thousands of workers from the Federal Emergency Management Agency, the national disaster organisation, are being deployed in North Carolina to assess the damage.

The North Carolina governor, Bev Perdue, interviewed on the NBC Today programme, said the storms had ripped through homes as if they were made of paper.

Tornadoes rip through southern US states – in pictures

guardian.co.uk, Monday 18 April 2011 – A savage storm system has left dozens dead across the southern United States and hundreds of thousands without power, with North Carolina alone hit by 62 tornadoes

A tornado flattened most of this home in the LaGrange subdivision in Fayetteville, North Carolina

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A car is swallowed up by a hole left by the tree, uprooted as a tornado passed just south of downtown Raleigh, North Carolina

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People walk through a devastated landscape after a tornado ripped through the Cottonade neighbourhood near Fort Bragg, North Carolina

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Nathaniel Ramey, left, comforts Megan Hurst at her grandmother’s house in Askewville, North Carolina

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Jenn Zezza, centre, joins volunteers to help sort through what was the office of a home on Serendipity Drive, in the McKinley Mill subdivision in Raleigh, North Carolina, after it was flattened by the tornado

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An aerial photo shows tornado damage at the Lowe’s hardware store in Sanford, North Carolina

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Annina Purdy, who was inside the Lowe’s hardware store in Sanford, North Carolina, when a tornado destroyed the building, returns to the car park to retrieve her belongings

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Steve Sawyer sorts through debris at a home which was destroyed by the tornado that swept through Gloucester, Virginia, on Saturday night

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Mary Grady sits in her neighbour’s yard in Askewville, North Carolina, where she weathered the tornado

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A home lies wrecked in the wake of a tornado that ripped through Gloucester, Virginia

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Governor Robert Bentley looks at family photos with Henley Hollon, whose brother, niece and nephew were all killed when their homes were twisted from their foundations by the tornado in Boone’s Chapel, Alabama

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guardian.co.uk, Monday 18 April 2011 – Deborah Dulow cleans up her father’s house in Askewville, North Carolina

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guardian.co.uk, Monday 18 April 2011- An aerial photo shows some of the approximately 30 houses severely damaged or destroyed by a tornado in the St Andrews neighbourhood just south of Sanford, North Carolina

Nuclear reactors provide about 1/3 of the electricity generated in Virginia. Virginia has commercial nuclear power plants at two locations, with two reactors each in Louisa County (North Anna 1 and North Anna 2) and Surry County (Surry 1 and Surry 2). The plants are most efficient when running at a steady rate, so they are used for baseload rather than peaking power.

Baseload plants run 24 hours per day and supply the electricity needed even when demand is at its lowest level. Peaking plants are turned on and off during the day, and supply extra energy needed in the morning (when people wake up, get ready for work/school, and turn on lights/hairdryers etc.) or in the evening (when people come home and cook dinner, do laundry, etc.).

One-third of the electricity distributed by Dominion Resources is produced by these two plants, and it has plans to add a new 1,600 megawatt reactor at the North Anna site. The third reactor, if built, would use a pressurized water reactor designed by Mitsubishi Heavy Industries.

The company recognizes the risks of using nuclear fuel, and the economics of the private utility are affected by its costs to manage those risks – including the day in the future when the nuclear power plants must be closed permanently (decommissioned). In its 2005 Annual Report, Dominion reported that it had set aside $2.6 billion to satisfy the Nuclear Regulatory Commission’s minimum financial assurance amounts for the future decommissioning of its nuclear facilities, but this may not equal the total that actually could be required.1

There are inherent risks in the operation of nuclear facilities. Dominion operates nuclear facilities that are subject to inherent risks. These include the threat of terrorist attack and ability to dispose of spent nuclear fuel, the disposal of which is subject to complex federal and state regulatory constraints. These risks also include the cost of and Dominion�s ability to maintain adequate reserves for decommissioning, costs of plant maintenance and exposure to potential liabilities arising out of the operation of these facilities. Dominion maintains decommissioning trusts and external insurance coverage to manage the financial exposure to these risks. However, it is possible that costs arising from claims could exceed the amount of any insurance coverage.

Fear of nuclear power after the Three Mile Island incident in 1979 limited the development of additional nuclear power plants in Virginia as a source for electricity. To present the case that nuclear power is safe, Dominion has visitor centers at each plant and even an online tour of a nuclear power plant.

Disaster plans have been developed for the reactors in Virginia (and for an incident at Calvert Cliffs in nearby Maryland) to evacuate people within 10 miles of North Anna Power Station (with a protected action zone for Caroline, Hanover, Louisa, Orange, and Spotsylvania counties) and Surry Power Station (with a protected action zone for Isle of Wight, James City, Surry, York counties and the cities of Newport News and Williamsburg). There are also plans to protect dairy products and crops within 50 miles.

The two nuclear reactors at the University of Virginia reactor in Charlottesville – the 100-watt “Cooperatively Assembled Virginia Low-Intensity Educational Reactor” (CAVALIER) and 2-megawatt University of Virginia Reactor (UVAR) were decommissioned in 1988 and 1998.

The Army Nuclear Power Program, based at Fort Belvoir, built and tested two small nuclear power plants at that site. It created the first nuclear power plant to generate electricity in Virginia, the 10-megawatt SM-1. The Army claims the SM-1 “was the first nuclear power reactor to provide electricity to a commercial power grid in the U.S.,”2 before it was deactivated in 1973. That power plant was an early model of what the Army expected to be many small nuclear power plants built for deployment to locations without electricity or conventional petroleum-based fuels, places that were not “on the grid” in an industrialized location.3

In November 1963, an Army study submitted to the Department of Defense (DOD) proposed employing a military compact reactor (MCR) as the power source for a nuclear-powered energy depot, which was being considered as a means of producing synthetic fuels in a combat zone for use in military vehicles. MCR studies, which had begun in 1955, grew out of the Transportation Corps’ interest in using nuclear energy to power heavy, overland cargo haulers in remote areas. These studies investigated various reactor and vehicle concepts, including a small liquid-metal-cooled reactor, but ultimately the concept proved impractical.

The energy depot, however, was an attempt to solve the logistics problem of supplying fuel to military vehicles on the battlefield. While nuclear power could not supply energy directly to individual vehicles, the MCR could provide power to manufacture, under field conditions, a synthetic fuel as a substitute for conventional carbon-based fuels.

The Army also tested its last nuclear power plant in Virginia. The MH-1A reactor capable of producing as much as 45 megawatts was installed in a World War Two Liberty ship, renamed the USS Sturgis after the recently-deceased Chief of the US Army Corps of Engineers. The ship’s propulsion system was removed, in order to make space for the rector. After a successful test of the reactor at Gunston Cove on the Potomac River, the floating power plant was towed to the Panama Canal, where it operated as a 10-megawatt power barge during the Vietnam War. The nuclear-generated electricity replaced output from a hydropower plant, allowing more water from Gatun Lake to be used for ship transits.4

Both the SM-1 and MH-1A reactors have now been deactivated. The Army may wait as long as 50 years for radiation to decrease before complete decommissioning of the reactors.5 The USS Sturgis has been placed in the Reserve Fleet in the James River before it is recycled.6

The Navy has continued its nuclear power program in Virginia, installing and refueling nuclear reactors in aircraft carriers and submarines at Newport News.

(NOTE: In many Virginia communities, hospitals and dentist offices have radioactive isotopes in various medical equipment, but these are generating radiation for X-rays and other medical purposes rather than power.)

Northrop Grumman Newport News (“We are the nation’s sole designer, builder and refueler of nuclear-powered aircraft carriers and one of only two companies capable of designing and building nuclear-powered submarines.”)